Gene Transcriptional Activity Research Articles

Delta.AR: An augmented reality-based visualization platform for 3D genome

Delta.AR: An augmented reality-based visualization platform for 3D genome

Ustilaginoidea virens modulates lysine 2-hydroxyisobutyrylation in rice flowers during infection.

The post-translational modification lysine 2-hydroxyisobutyrylation (Khib ) plays an important role in gene transcription, metabolism, and enzymatic activity. Khib sites have been identified in rice (Oryza sativa). However, the Khib status of proteins in rice flowers during pathogen infection remains unclear. Here, we report a comprehensive identification of Khib -modified proteins in rice flowers, and the changes in these proteins during infection with the fungal pathogen Ustilaginoidea virens. By using a tandem mass tag-based quantitative proteomics approach, we identified 2,891 Khib sites on 964 proteins in rice flowers. Our data demonstrated that 2-hydroxyisobutyrylated proteins are involved in diverse biological processes. Khib levels were substantially reduced upon infection with U. virens. Chromatin immunoprecipitation polymerase chain reaction (PCR) and reverse transcription quantitative PCR analyses revealed that histone Khib is involved in the expression of disease-resistance genes. More importantly, most quantified sites on core histones H3 were downregulated upon U. virens infection. In addition, the histone deacetylases HDA705, HDA716, SRT1, and SRT2 are involved in the removal of Khib marks in rice. HDA705 was further confirmed to negatively regulate rice disease resistance to pathogens U. virens, Magnaporthe oryzae, and Xanthomonas oryzae pv. oryzae (Xoo). Our data suggest that U. virens could modulate Khib in rice flowers during infection.

Morphological, phenological, and transcriptional analyses provide insight into the diverse flowering traits of a mutant of the relic woody plant Liriodendron chinense

Flowering is crucial to plant reproduction and controlled by multiple factors. However, the mechanisms underlying the regulation of flowering in perennial plants are still largely unknown. Here, we first report a super long blooming 1 (slb1) mutant of the relict tree Liriodendron chinense possessing a prolonged blooming period of more than 5 months, in contrast to the 1 month blooming period in the wild type (WT). Phenotypic characterization showed that earlier maturation of lateral shoots was caused by accelerated axillary bud fate, leading to the phenotype of continuous flowering in slb1 mutants. The transcriptional activity of genes related to hormone signaling (auxin, cytokinin, and strigolactone), nutrient availability, and oxidative stress relief further indicated active outgrowth of lateral buds in slb1 mutants. Interestingly, we discovered a unique FT splicing variant with intron retention specific to slb1 mutants, representing a potential causal mutation in the slb1 mutants. Surprisingly, most slb1 inbred offspring flowered precociously with shorter juvenility (~4 months) than that (usually 8–10 years) required in WT plants, indicating heritable variation underlying continuous flowering in slb1 mutants. This study reports an example of a perennial tree mutant that flowers continuously, providing a rare resource for both breeding and genetic research.

CTLA4 promoter hypomethylation is a negative prognostic biomarker at initial diagnosis but predicts response and favorable outcome to anti-PD-1 based immunotherapy in clear cell renal cell carcinoma

BackgroundIn metastatic clear cell renal cell carcinoma (ccRCC), different combination therapies, each including anti-PD-1 immune checkpoint blockade (ICB), are applied as first-line treatment. Robust predictive biomarkers for rational upfront therapy...

Determination of genetic effects and functional SNPs of bovine HTR1B gene on milk fatty acid traits

BackgroundOur previous genome-wide association study (GWAS) on milk fatty acid traits in Chinese Holstein cows revealed, the SNP, BTB-01556197, was significantly associated with C10:0 at genome-wide level (P = 0.0239). It was located in the down-stream of 5-hydroxytryptamine receptor 1B (HTR1B) gene that has been shown to play an important role in the regulation of fatty acid oxidation. Hence, we considered it as a promising candidate gene for milk fatty acids in dairy cattle. In this study, we aimed to investigate whether the HTR1B gene had significant genetic effects on milk fatty acid traits.ResultsWe re-sequenced the entire coding region and 3000 bp of 5′ and 3′ flanking regions of HTR1B gene. A total of 13 SNPs was identified, containing one in 5′ flanking region, two in 5′ untranslated region (UTR), two in exon 1, five in 3′ UTR, and three in 3′ flanking region. By performing genotype-phenotype association analysis with SAS9.2 software, we observed that 13 SNPs were significantly associated with medium-chain saturated fatty acids such as C6:0, C8:0 and C10:0 (P < 0.0001 ~ 0.042). With Haploview 4.1 software, linkage disequilibrium (LD) analysis was performed. Two haplotype blocks formed by two and ten SNPs were observed. Haplotype-based association analysis indicated that both haplotype blocks were strongly associated with C6:0, C8:0 and C10:0 as well (P < 0.0001 ~ 0.0071). With regards to the missense mutation in exon 1 (g.17303383G > T) that reduced amino acid change from alanine to serine, we predicted that it altered the secondary structure of HTR1B protein with SOPMA. In addition, we predicted that three SNPs in promoter region, g.17307103A > T, g.17305206 T > G and g.17303761C > T, altered the binding sites of transcription factors (TFs) HMX2, PAX2, FOXP1ES, MIZ1, CUX2, DREAM, and PPAR-RXR by Genomatix. Of them, luciferase assay experiment further confirmed that the allele T of g.17307103A > T significantly increased the transcriptional activity of HTR1B gene than allele A (P = 0.0007).ConclusionsIn conclusion, our findings provided first evidence that the HTR1B gene had significant genetic effects on milk fatty acids in dairy cattle.

К вопросу о патогенетических механизмах влияния ожирения на уровень витамина D

The influence of obesity on human health, as a multifactorial and multigenic disorder, is a rather complex, interdisciplinary and at the same time extremely urgent problem of modern society. Vitamin D deficiency is one of the consequences of obesity that negatively affects a person’s life expectancy. Vitamin D deficiency is rightfully considered a silent, non-infectious metabolic pandemic of the 21st century. Its significant role in the functioning of the human body is deep and multifaceted, since vitamin D is an integral regulator of the transcriptional activity of genes that control 3–5% of the human genome. There are ongoing discussions among experts in the medical community about the negative impact of obesity on 25 (OH) D levels, and the opposite hypothesis is also being discussed, where vitamin D deficiency is considered an independent risk factor for obesity. Both external causes of the formation of vitamin D deficiency against the background of excessive deposition of adipose tissue and internal metabolic processes underlying the pathogenetic association are analyzed two pathological conditions.

To the question of the pathogenetic mechanisms of the influence of obesity on the level of vitamin D

The influence of obesity on human health, as a multifactorial and multigenic disorder, is a rather complex, interdisciplinary and at the same time extremely urgent problem of modern society. Vitamin D deficiency is one of the consequences of obesity that negatively affects a person’s life expectancy. Vitamin D deficiency is rightfully considered a silent, non-infectious metabolic pandemic of the 21st century. Its significant role in the functioning of the human body is deep and multifaceted, since vitamin D is an integral regulator of the transcriptional activity of genes that control 3–5% of the human genome. There are ongoing discussions among experts in the medical community about the negative impact of obesity on 25 (OH) D levels, and the opposite hypothesis is also being discussed, where vitamin D deficiency is considered an independent risk factor for obesity. Both external causes of the formation of vitamin D deficiency against the background of excessive deposition of adipose tissue and internal metabolic processes underlying the pathogenetic association are analyzed two pathological conditions.

Transcriptional study reveals a potential leptin-dependent gene regulatory network in zebrafish brain

The signal mediated by leptin hormone and its receptor is a major regulator of body weight, food intake and metabolism. In mammals and many teleost fish species, leptin has an anorexigenic role and inhibits food intake by influencing the appetite centres in the hypothalamus. However, the regulatory connections between leptin and downstream genes mediating its appetite-regulating effects are still not fully explored in teleost fish. In this study, we used a loss of function leptin receptor zebrafish mutant and real-time quantitative PCR to assess brain expression patterns of several previously identified anorexigenic genes downstream of leptin signal under different feeding conditions (normal feeding, 7-day fasting, 2 and 6-h refeeding). These downstream factors include members of cart genes, crhb and gnrh2, as well as selected genes co-expressed with them based on a zebrafish co-expression database. Here, we found a potential gene expression network (GRN) comprising the abovementioned genes by a stepwise approach of identifying co-expression modules and predicting their upstream regulators. Among the transcription factors (TFs) predicted as potential upstream regulators of this GRN, we found expression pattern of sp3a to be correlated with transcriptional changes of the downstream gene network. Interestingly, the expression and transcriptional activity of Sp3 orthologous gene in mammals have already been implicated to be under the influence of leptin signal. These findings suggest a potentially conserved regulatory connection between leptin and sp3a, which is predicted to act as a transcriptional driver of a downstream gene network in the zebrafish brain.

Anther dehiscence is regulated by gibberellic acid in yellow lupine (Lupinus luteus L.)

BackgroundAnther dehiscence resulting in the release of pollen grains is tightly regulated in a spatiotemporal manner by various factors. In yellow lupine (Lupinus luteus L.), a species that shows cleistogamy, the anthers split before the flowers open, but the course and regulation of this process are unknown. The specific control of anther development takes place via hormonal pathways, the wide action of which ensures reproductive success. In our previous research concerning flower and early pod development in yellow lupine, we showed that the lowest transcript level of LlDELLA1, a main repressor of gibberellin (GA) signalling, occurs approximately at the time of anther opening; therefore, the main purpose of this study was to precisely investigate the gibberellic acid (GA3)-dependent regulation of the anther dehiscence in this species.ResultsIn this paper, we showed the specific changes in the yellow lupine anther structure during dehiscence, including secondary thickening in the endothecium by lignocellulosic deposition, enzymatic cell wall breakdown at the septum/stomium and cell degeneration via programmed cell death (PCD), and identified several genes widely associated with this process. The expression profile of genes varied over time, with the most intense mRNA accumulation in the phases prior to or at the time of anther opening. The transcriptional activity also revealed that these genes are highly coexpressed and regulated in a GA-dependent manner. The cellular and tissue localization of GA3 showed that these molecules are present before anther opening, mainly in septum cells, near the vascular bundle and in the endothecium, and that they are subsequently undetectable. GA3 localization strongly correlates with the transcriptional activity of genes related to GA biosynthesis and deactivation. The results also suggest that GA3 controls LlGAMYB expression via an LlMIR159-dependent pathway.ConclusionsThe presented results show a clear contribution of GA3 in the control of the extensive anther dehiscence process in yellow lupine. Understanding the processes underlying pollen release at the hormonal and molecular levels is a significant aspect of controlling fertility in this economically important legume crop species and is of increasing interest to breeders.

Abstract 1401: MYC mediates retinoic acid resistance by suppressing cellular retinoic acid-binding protein (CRABP2) transcription in HER2-enriched breast cancers

Abstract Introduction: HER2-positive (HER2+) breast cancers express high levels of the growth-promoting HER2 protein. The development of a targeted drug, trastuzumab, has greatly improved clinical outcome for HER2+ patients. However, intrinsic and acquired resistance to trastuzumab are common. Clearly, additional therapeutic interventions are required for the clinical management of HER2-enriched breast cancers. Retinoic acid (RA) is a vital signaling molecule that regulates multiple biological processes, including cell proliferation, differentiation, and death. RA has been successfully used in the treatment of acute promyelocytic leukemia. RA also holds promise for the treatment of solid cancers like breast cancer. RA action is mediated through transcription factor RARα and the RA binding protein CRABP2, which deliver RA to RARα in the nucleus. The HER2 gene (ERBB2) is frequently co-amplified with the gene encoding RARα, a key determinant of RA sensitivity. It seems surprising, therefore, that HER2+ breast cancers are refractory to RA treatment. MYC is an oncogene that inhibits RARα activity in leukemia cells. Importantly, MYC is preferentially amplified and overexpressed in HER2+ breast cancers. My research aims to elucidate the mechanism underlying RA resistance in HER2+ breast cancers, with a special focus on the role of MYC. Hypothesis: MYC attenuates RA action by inhibiting the CRABP2-RARα pathway. Results: RNA levels of MYC are negatively correlated with CRABP2 RNA levels. Depletion of MYC upregulates CRABP2 at both the RNA and protein levels. Furthermore, we found that MYC binds to the CRABP2 promoter region suggesting that MYC may directly suppress CRABP2 gene transcription activity. Our results show that ectopic expression of MYC inhibits, whereas depletion of MYC activates RAR activity. Consistently, ectopic expression of MYC increases RA resistance, whereas depletion of MYC sensitizes cells to RA treatment. When CRABP2 is depleted along with MYC-knockdown, cell proliferation is rescued, suggesting that MYC mediates RA resistance, at least partially through downregulation of CRABP2. We also found that RA treatment enhances trastuzumab responsiveness in HER2+ breast cancer cells. Significance: This study sheds light on the role and mechanism of MYC in governing RA resistance in HER2+ breast cancer cells. Our results support the use of RA and trastuzumab for the treatment of subsets of patients with HER2+/low MYC breast cancers. Citation Format: Won-Shik Choi, Rong-Zong Liu, Roseline Godbout. MYC mediates retinoic acid resistance by suppressing cellular retinoic acid-binding protein (CRABP2) transcription in HER2-enriched breast cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1401.

Exogenous orexin-A downregulates luteinizing hormone secretory activity in prepubertal female rats.

Orexin-A is a neuropeptide synthesized in the lateral hypothalamus. Orexin-A immunoreactive fibres overlap distribution with GnRH neurons. In adult rats, orexin A is known to affect LH secretion via GnRH release modulation. Because data concerning the impact of orexin-A on the hypothalamo-pituitary axis activity are limited, we focused on the involvement of orexin-A and receptors of NPY in the modulation of LH release and LH subunit b (Lhb) mRNA expression in prepubertal female rats. Forty immature female Wistar rats were divided into 4 groups and received 2 intracerebroventricular (icv) microinjections of: 1 - artificial cerebrospinal fluid (CSF) (controls); 2 - CSF followed by orexin A; 3 - selective NPY receptor antagonist (BIBP) followed by CSF; 4 - BIBP followed by orexin A. One hour after the last microinjection, all rats were decapitated. Trunk blood was collected, and serum was stored at -20°C for the LH RIA examination. The adenohypophysis was immediately excised, flash-frozen, and kept at -80°C for RNA extraction. Real-time PCR amplification was carried out, and relative Lhb gene expression was calculated. In comparison to the CSF-treated controls with a mean LH serum concentration of 0.40 ± 0.02 ng/mL, the mean LH serum level was diminished both after orexin-A (0.27 ± 0.01 ng/mL) and after BIBP (0.30 ± 0.02 ng/mL) icv microinjections. In the presence of BIBP, orexin-A more effectively inhibited LH release (0.20 ± 0.01 ng/mL) when compared to the BIBP-treated group. Orexin-A and BIBP exerted a consistent inhibitory effect on Lhb mRNA expression levels in the anterior pituitary gland. In comparison to the CSF-treated controls, orexin-A, and BIBP-treated females responded with, respectively, 35% and 40% reduction of Lhb mRNA expression. Orexin-A and BIBP co-administration evoked a further reduction of Lhb gene transcriptional activity. Orexin-A exerts a down-regulatory effect on LH synthesis and release in immature female rats. Considering that Y1R-oriented down-regulation of endogenous NPY activity did not reverse the suppressive effect of exogenous orexin-A, it might be suggested that NPY and orexin A systems can operate independently to affect gonadotropin activity in the anterior pituitary of the immature female rats.

Overexpression of Histone Demethylase KDM6B in the Hematopoietic Compartment Promotes the Effect of Innate Immune Activation and Results in Myelodysplastic Syndrome (MDS)-like Phenotype in Mice

The histone demethylase KDM6B regulates transcriptional activity of genes involved in innate immune signals and controls differentiation of hematopoietic cells. Our laboratory previously reported that KDM6B is overexpressed in bone marrow (BM) hematopoietic stem and progenitor cells (HSPCs) of over 50% MDS pts (Leukemia 2013). Pharmacologic targeting of KDM6B has shown pre-clinical activity in several neoplasms such as glioma and ALL. It still remains to be elucidated whether KDM6B overexpression directly alters hematopoiesis, in order to test the hypothesis that overexpression of KDM6B contributes to aberrant epigenetic and innate immune signal in MDS and thus forms an important pathological mechanism and potential therapeutic target.Here we report an animal model of KDM6B overexpression in mouse hematopoietic compartment (Vav-KDM6B). In 20-wk old mice, KDM6B overexpression led to mild phenotype including reduced white cell count (WBC) in peripheral blood (PB) (15% p<0.05 N=47) and decreased LSK in BM (20% p<0.05 N=12). When exposed to chronic low dose Toll-like receptor ligand lipopolysaccharide (LPS) (6mg every other day, i.p. 6 wks), phenotype severity was more profound in Vav-KDM6B mice than in wildtype (WT) mice. First, hematopoietic cell numbers in both PB and BM were significantly reduced: LPS led to a 40% decrease of PB WBC (p<0.01 N=17) and a 38% decrease of BM cell (p<0.01 N=13 Fig 1A) in KDM6B mice, compared to 20% and 28% reduction respectively in WT mice treated by LPS. Second, both number and repopulating function of BM long term (LT) HSC were severely compromised: LPS led to decrease of BM LT-HSC by 52% (p<0.01 N=13) in KDM6B mice compared to a 35% decrease in WT mice. Functionally, colonies formed in methylcellulose by LSKs of LPS treated KDM6B mice decreased by 75% (p<0.01 N=13) at 2nd plating, whereas LPS led to a reduction of 60% for WT-LSK colony formation at 2nd plating. Similar effect was also observed when BM repopulating capacity was evaluated by chimerism (CD45.2:CD45.1) in competitive transplantation assay (p<0.05 N=11). Third, increase of megakaryocytic dysplasia was documented in BM of LPS treated KDM6B mice compared to WT counterparts (Fig 1B).To identify KDM6B overexpression mediated molecular signals under innate immune stimuli, we performed genome-wide transcriptome study using BM LSK of treated mice. Results reveal that over 130 genes were more profoundly activated by LPS in LSK of Vav-KDM6B than in WT LSK. Gene set enrichment assays (GSEA) indicated that major molecular pathways related to these genes include MDS-relevant signals, such as inflammatory and complement innate immune signals, MAPK pathway, as well as activated gene signature of RPS14 knockout in human BM CD34+ cell. We also performed RNA-Seq analysis in BM CD34+ HSPCs of MDS (N=26) and healthy controls (N=10). Results confirmed that a significant proportion of these genes (N>20) are overexpressed in MDS patients. Furthermore, we demonstrated in mouse BM cells that KDM6B overexpression mediates histone H3K4 and H3K27 methylation at promoters of several key innate immune genes towards transcription activation.We next evaluated effect of pharmacological KDM6B targeting using a highly specific KDM6B inhibitor (GSK-J4). At relatively low-dose (0.5mM), GSK-J4 could increase in vitro colony formation of LSKs of LPS treated KDM6B mice by 80% (p<0.05) at 2nd plating. Injection of GSK-J4 (160mg once a week, 5 weeks) resulted in 50% increase of WBM cells in LPS treated Vav-KDM6B mice (p<0.05). These results suggest that GSK-J4 can improve compromised hematopoiesis of Vav-KDM6B mice. We next treated primary BM HSPCs isolated from patients with low risk MDS (N=11) with GSK-J4. Results indicated that at 0.5mM, GSK-J4 could improve colony formation of MDS CD34+ cells (p=0.05). Flow cytometry analysis using cells from colonies indicated that GSK-J4 led to increased myeloid mark CD11b (p=0.08) and reduced apoptotic mark annexin-V (p<0.05). The same concentration of GSK-J4 did not affect colony formation of normal BM CD34+ HSPCs isolated from healthy donors (N=4).Taken together, our results indicate that overexpression of KDM6B mediates the hyperactivation of innate immune signals and has a functional impact in BM HSPCs, supporting role for KDM6B overexpression in MDS pathogenesis. Furthermore, our study also indicates that pharmacological inhibition of KDM6B may have therapeutic potential in MDS. [Display omitted] DisclosuresKhoury:Kiromics: Research Funding; Angle: Research Funding; Stemline Therapeutics: Research Funding; Pfizer: Research Funding.

Genetic Variants and Functional Analyses of the ATG16L1 Gene Promoter in Acute Myocardial Infarction.

BackgroundAcute myocardial infarction (AMI), a common complex disease caused by an interaction between genetic and environmental factors, is a serious type of coronary artery disease and is also a leading cause of death worldwide. Autophagy-related 16-like 1 (ATG16L1) is a key regulatory factor of autophagy and plays an important role in induced autophagy. In the cardiovascular system, autophagy is essential to preserve the homeostasis and function of the heart and blood vessels. No studies have hitherto examined the association between AMI and ATG16L1 gene promoter.MethodsWe conducted a case-control study, using polymerase chain reaction and sequencing techniques, dual luciferase reporter assay, and electrophoretic mobility shift assay, to analyze genetic and functional variation in the ATG16L1 gene promoter between AMI and controls. A variety of statistical analyses were used to analyze the allele and genotype frequencies and the relationship between single-nucleotide polymorphisms (SNPs) and AMI.ResultsIn all, 10 SNPs and two DNA-sequence variants (DSVs) were identified in 688 subjects, and three ATG16L1 gene promoter mutations [g.233250693 T > C (rs185213911), g.233250946 G > A (rs568956599), g.233251133 C > G (rs1301744254)] that were identified in AMI patients significantly altered the transcriptional activity of ATG16L1 gene promoter in HEH2, HEK-293, and H9c2 cells (P < 0.05). Further electrophoretic mobility shift assays indicated that the SNPs affected the binding of transcription factors (P < 0.01).ConclusionATG16L1 gene promoter mutations in AMI patients may affect the binding of transcription factors and change the transcriptional activity of the ATG16L1 gene, changing the level of autophagy and contributing to the occurrence and development of AMI as rare and low-frequency risk factors.

Genetic and epigenetic bases of prostate tumor cell radioresistance.

Radiation therapy plays aleading role in the treatment of prostate cancer, but the emergence of radioresistant forms of this disease dictates the need for apersonalized ap-proach based on the data from genetic and epigenetic markers. Such markers include the copy number variation as well as gene and microRNA expression. The aim of the study was to validate the list of potential predictors of radioresistance of prostate tumor cells in amodel experiment based on the determination of gene copy number variation, gene transcriptional activity and microRNA expression. The study used aPC-3prostate cancer cell culture. The determination of the relative copy number variation and expression of 32genes (BRCA1, BRCA2, PTEN, CASP3, CASP8, BAX, BCL2, CASP9, P53, MDM2, AKT1, ATM, BRIP1, CDK1, CDKN1B, CCND1, CCND3, FGFR2, KU70, RAD50, RAP80, Rif1, RNF168, TopBP1, HIST, H2AX, EXO1, XRCC4, RBBP8, EP300, LIG4, C-FLIP), as well as 15microRNAs (let-7, miR15a/&#8202;16, miR-17, miR-18a, miR-21, miR-24, miR-26b, miR-99a, miR-100, miR-101, miR-106a, miR-663a, miR-143, miR-145) was performed using the real-time quantitative polymerase chain reaction method. It was found that daily irradiation of PC-3cells on aNovalis TX linear accelerator at doses of 6and 7Gy for 5days leads to asignificant decrease in the total number of cells and the number of viable cells. Nevertheless, after 5days of irradiation, about 15% of the initial number of prostate tumor cells retained their viability, which is due to their special genetic and epigenetic characteristics: increased copy number and expression of genes BRCA2, CDK1, CDKN1B, H2AX, RAD50, XRCC4, RBBP8and EP300and reduced copy number and expression of CCND3, TP53, and BCL2genes, as well as differential expression of sixmicroRNAs (hsa-miR-18a-5p, hsa-miR-24-5p, hsa-miR-99a-5p, hsa-miR-100-5p, hsa-miR-145-5p, hsa-let-7a-3p). This study enabled to identify genetic and epigenetic markers of prostate tumor cells resistance to radiation therapy.

Equid herpesvirus-1 Distribution in Equine Lymphoid and Neural Tissues 70 Days Post Infection.

Equid herpesvirus-1 (EHV-1) causes respiratory disease, abortion and myeloencephalopathy in horses worldwide. As member of the Alphaherpesvirinae, latency is key to EHV-1 epidemiology. EHV-1 latent infection has been detected in the trigeminal ganglion (TG), respiratory associated lymphoid tissue (RALT) and peripheral blood mononuclear cells (PBMC) but additional locations are likely. The aim of this study was to investigate the distribution of viral DNA throughout the equine body. Twenty-five horses divided into three groups were experimentally infected via intranasal instillation with one of three EHV-1 viruses and euthanized on Day 70, post infection. During necropsy, TG, various sympathetic/parasympathetic ganglia of head, neck, thorax and abdomen, spinal cord dorsal root ganglia, RALT, mesenteric lymph nodes, spleen and PBMC of each horse were collected. Genomic viral loads and L-(late) gene transcriptional activity in each tissue and PBMC were measured using qPCR. In addition, immunohistochemistry (IHC) was applied on neural parenchyma tissue sections. EHV-1 DNA was detected in many neural and lymphoid tissue sections, but not in PBMC. L-gene transcriptional activity was not detected in any sample, and translational activity was not apparent on IHC. Tissue tropism differed between the Ab4 wild type and the two mutant viruses.

The interplay of seizures-induced axonal sprouting and transcription-dependent Bdnf repositioning in the model of temporal lobe epilepsy.

The Brain-Derived Neurotrophic Factor is one of the most important trophic proteins in the brain. The role of this growth factor in neuronal plasticity, in health and disease, has been extensively studied. However, mechanisms of epigenetic regulation of Bdnf gene expression in epilepsy are still elusive. In our previous work, using a rat model of neuronal activation upon kainate-induced seizures, we observed a repositioning of Bdnf alleles from the nuclear periphery towards the nuclear center. This change of Bdnf intranuclear position was associated with transcriptional gene activity. In the present study, using the same neuronal activation model, we analyzed the relation between the percentage of the Bdnf allele at the nuclear periphery and clinical and morphological traits of epilepsy. We observed that the decrease of the percentage of the Bdnf allele at the nuclear periphery correlates with stronger mossy fiber sprouting-an aberrant form of excitatory circuits formation. Moreover, using in vitro hippocampal cultures we showed that Bdnf repositioning is a consequence of transcriptional activity. Inhibition of RNA polymerase II activity in primary cultured neurons with Actinomycin D completely blocked Bdnf gene transcription and repositioning occurring after neuronal excitation. Interestingly, we observed that histone deacetylases inhibition with Trichostatin A induced a slight increase of Bdnf gene transcription and its repositioning even in the absence of neuronal excitation. Presented results provide novel insight into the role of BDNF in epileptogenesis. Moreover, they strengthen the statement that this particular gene is a good candidate to search for a new generation of antiepileptic therapies.

A Novel Signaling Pathway Connects Thiamine Biosynthesis, Bacterial Respiration, and Production of the Exopolysaccharide Amylovoran in Erwinia amylovora.

Erwinia amylovora is a plant pathogen causing necrotrophic fire blight disease of apple, pear, and other rosaceous plants. This bacterium colonizes host vascular tissues via the production of exopolysaccharides (EPSs) including amylovoran. It is well-established that the nearly ubiquitous plasmid pEA29 of E. amylovora is an essential virulence factor, but the underlying mechanism remains uncharacterized. Here, we demonstrated that pEA29 was required for E. amylovora to produce amylovoran and to form a biofilm, and this regulation was dependent on the thiamine biosynthesis operon thiOSGF. We then conducted carbohydrate and genetic analyses demonstrating that the thiamine-mediated effect on amylovoran production was indirect, as cells lacking thiOSGF produced an EPS that did not contain glucuronic acid, one of the key components of amylovoran, whereas the transcriptional activity and RNA levels of the amylovoran biosynthesis genes were not altered. Alternatively, addition of exogenous thiamine restored amylovoran production in the pEA29-cured strain of E. amylovora and positively impacted amylovoran production in a dose-dependent manner. Individual deletion of several chromosomal thiamine biosynthesis genes also affected amylovoran production, implying that a complete thiamine biosynthesis pathway is required for the thiamine-mediated effect on amylovoran production in E. amylovora. Finally, we determined that an imbalanced tricarboxylic acid cycle negatively affected amylovoran production, which was restored by addition of exogenous thiamine or overexpression of the thiOSGF operon. In summary, our report revealed a novel signaling pathway that impacts E. amylovora virulence in which thiamine biosynthesis enhances bacterial respiration that provides energetic requirements for the biosynthesis of EPS amylovoran.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Rootstock effects on scion gene expression in maritime pine

Pines are the dominant conifers in Mediterranean forests. As long-lived sessile organisms that seasonally have to cope with drought periods, they have developed a variety of adaptive responses. However, during last decades, highly intense and long-lasting drought events could have contributed to decay and mortality of the most susceptible trees. Among conifer species, Pinus pinaster Ait. shows remarkable ability to adapt to different environments. Previous molecular analysis of a full-sib family designed to study drought response led us to find active transcriptional activity of stress-responding genes even without water deprivation in tolerant genotypes. To improve our knowledge about communication between above- and below-ground organs of maritime pine, we have analyzed four graft-type constructions using two siblings as rootstocks and their progenitors, Gal 1056 and Oria 6, as scions. Transcriptomic profiles of needles from both scions were modified by the rootstock they were grafted on. However, the most significant differential gene expression was observed in drought-sensitive Gal 1056, while in drought-tolerant Oria 6, differential gene expression was very much lower. Furthermore, both scions grafted onto drought-tolerant rootstocks showed activation of genes involved in tolerance to abiotic stress, and is most remarkable in Oria 6 grafts where higher accumulation of transcripts involved in phytohormone action, transcriptional regulation, photosynthesis and signaling has been found. Additionally, processes, such as those related to secondary metabolism, were mainly associated with the scion genotype. This study provides pioneering information about rootstock effects on scion gene expression in conifers.

Functional characterization and expression profile of microsomal FAD2 and FAD3 genes involved in linoleic and α-linolenic acid production in Leucas cephalotes.

The online version contains supplementary material available at 10.1007/s12298-021-01016-z.

Iron Sulfide Enhanced the Dechlorination of Trichloroethene by Dehalococcoides mccartyi Strain 195.

Iron sulfide (FeS) nanoparticles have great potential in environmental remediation. Using the representative species Dehalococcoides mccartyi strain 195 (Dhc 195), the effect of FeS on trichloroethene (TCE) dechlorination was studied with hydrogen and acetate as the electron donor and carbon source, respectively. With the addition of 0.2 mM Fe2+ and S2–, the dechlorination rate of TCE was enhanced from 25.46 ± 1.15 to 37.84 ± 1.89 μmol⋅L–1⋅day–1 by the in situ formed FeS nanoparticles, as revealed through X-ray diffraction. Comparing the tceA gene copy numbers between with FeS and without FeS, real-time polymerase chain reaction (PCR) indicated that the abundance of the tceA gene increased from (2.83 ± 0.13) × 107 to (4.27 ± 0.21) × 108 copies/ml on day 12. The transcriptional activity of key genes involved in the electron transport chain was upregulated after the addition of FeS, including those responsible for the iron–sulfur cluster assembly protein gene (DET1632) and transmembrane transport of iron (DET1503, DET0685), cobalamin (DET0685, DET1139), and molybdenum (DET1161) genes. Meanwhile, the reverse transcription of tceA was increased approximately five times on the 12th day. These upregulations together suggested that the electron transport of D. mccartyi strain 195 was enhanced by FeS for apparent TCE dechlorination. Overall, the present study provided an eco-friendly and effective method to achieve high remediation efficiency for organohalide-polluted groundwater and soil.